Can body blank preparing method



Dec. 24, 1940. G. v. HALLMAN CAN BODY BLANK PREPARING METHOD Filed March `6, 1939 W M E '.v M W. w V P mi' A] v Patented Dec. 24, 1940 PATENT OFFICE y CAN BODY BLANK PBEPABING ME'rHon George V. Hallman, River` Forest, Ill., assignor to Continental Can Company,

Inc., New York,

N. Y., a corporation of New York l Application March 6, 1939, Serial No. 260,196

The invention relates generally to the art of can making and primarily seeks to provide a novel method of preparing can body' blanks of black plate or mild steel, or principally the edge portions of the blanks which are to form the can body seams, so as to facilitate subsequent solder bonding of the can body seams.

Untreated black plate oxidizes when exposed to the air, and scale forms thereon which interferes with the solderadhering to the plate when it is attempted to solder side seams of cans formed from such plate. The present invention seeks to remedy this condition and make possible economical formation of cans from relatively inexpensive black plate by providing a novel method in which the edge portions only'of the black plate which are to be formed into side seams in the making-of the cans are first cleaned of oxidation and scale and then given a suitable metallic coating, preferably tin, so as to facilitate subsequent soldering,

In its more detailed nature, the invention resides `in the steps of pickle VVbath or otherwise.

cleaning the edge portions of the black `plate blanks which are to be formed into side seams,

and then bending the blanks and immersing the cleaned edge portions thereof in a coating bath to suitably plate said edge portions so as to facilitate Vsubsequent soldering thereof.

Another object of the invention is toprovide ar method of the character stated in which the pickling and tin plating steps are performed successively on continuously moving blackplate can body blanks. l C Another object of the invention is to include in the method the steps of treating the plated edge A portions to determine the thickness of the plating thereon, and of buing said plated edges.

- `With the above and other objects in view that 40 will hereinafter appear, the nature of the invention will be more fully understood by following the detailed description, the appended claims, and the several-views illustrated in the accompanying, drawing:

'45 In the drawing:

z claim. (ci. en -10.3)A

trated one manner of practicing the invention in which body blanks 5 to beformed into can bodies are moved by a conveyor 6 through a stationary horn or horse structure 1 so shaped as to receive the body blanks in fiat horizontal condition and 5 gradually turn the lateral -edge portions thereof downwardly- `in inverted U-shape as illustrated in Figure 2. The horn or horse structure diagrammatically illustrated in Figures 1, 2 and 3 is formed to include successively effective edge turn- 10 ing' portions, with a restoring or edge straightening portion following each edge turning portion, so that when passing through this structure each can body blank 5, horizontally received, will have its lateral edge portions turned downwardly in Il .inverted U-shape, then upwardly to restore the '.blank' to its flat' horizontal position, then down- Wardly to again form thev blank into inverted U- ofrnolten'v-tin. .'I'hisbath is covered -by a thin so depth of ux indicated at |10. By `reason of the provision of the successive pickling and tinning baths 8 and 9, the extreme lateral edge portions only of the blanks, 5 will be iirst pickled and cleaned of oxidation and scale and then receive a tin plating by immersion .in the flux covered tinning bath.

By practicing this method of handling the body blanks, the tin plating is provided only at the edge portions of the blanks which are to be subseo quently formed into side seam structures. Thus emcient solder bonding of the side seams is assured with the use of a minimum amount of tin.

After the body blanks leave the tinning bath they are edge treated=so as to determine the thickness of the tin' plating and to bun or polish this plating. In the diagrammatic illustration herein made, the blanks are illustrated as passing through suitable feed rollers Hand successively positioned abrading rolls i2 and buing rolls I3. See Figures 1, 4 and `5. 'I'he abrading rolls i2 may be adjustably mounted so as to reduce to the thickness desired the tin plating acquired by immersion in the bath 9, and the buing rolls I3 55 serve to suitably polish the plating reduced to the desired thickness.

In Figure 6 of the drawing a body blank 5 ,formed of black plate or mild steel is illustrated with an edge plating of tin applied to the lateral edge portions at the respective faces thereof as illustrated at Il. y

While I have referred herein specically t immersing the edge portions `of the can body blanks in a tin plating bath, the invention is not to be considered limited to plating with tin.,

The edge portions of the blanks may be immersed in any metallic plating bath suitable for y This bending of the blanks may take place Whilel they are continuously traveling, or the bending may be formed L during rest intervals of the blanks.

I claim: v

1. The method of preparing black plate can body blanks for formation into can bodies in which lthe side seams are soldered which comprises, continuously conveying the individual blanks in spaced and aligned relation with the edge portions thereof subsequently to be formed into canbody side seams disposed laterally and in the direction in which the blanks are being conveyed, successively passing said blanks over a pickling bath and a metallic plating bath, and bending the blanks so asto depress the lateral edge portions only thereof for immersion in said baths to the extent-to which said edges are to be used in the formation of can body side seams.

2. The method bf preparing black plate can body blanks for formation into can bodies in which the side seams are soldered which comprises, continuously conveying the individual blanks in spaced and aligned relation with the edge portions thereof 'subsequently to be formed into can body side seams disposed laterally and vin the direction in which the blanks are being conveyed, successively passing said blanks over a pickling bath and a metallic plating bath,

bending the blanks so asto depress the lateral 

